From: "John R. Strohm" <strohm@airmail.net>
Subject: Re: status of PL/I as a viable language
Date: Thu, 20 Feb 2003 17:30:45 -0600
Date: 2003-02-20T17:30:45-06:00 [thread overview]
Message-ID: <819A9E0CA1094B88.6E582670555DCA33.F06C4B2BCD076570@lp.airnews.net> (raw)
In-Reply-To: 3E554AF4.C8F0EF2E@yahoo.com
"Peter Flass" <peter_flass@yahoo.com> wrote in message
news:3E554AF4.C8F0EF2E@yahoo.com...
> "John R. Strohm" wrote:
> > The last bug I found and fixed at my last employer was a null pointer
> > access. That company has an internal coding policy that pointers will
> > ALWAYS be tested for null before being dereferenced.
>
> I would submit that this should be done by hardware, not software (i.e.
> location 0, assuming null is 0) should be fetch-protected from
> everywhere but a few O/S routines. Anything else is a colossal waste of
> computing resources.
On just about every machine I've ever dealt with, dereferencing a null
pointer throws a hardware trap. Dereferencing a null pointer is ALWAYS an
error. It may be a case of "This pointer should NEVER be null" or it may be
a case of "OK, there is no existing entry for this object, so we have to
create a new one".
Catching a hardware trap and recovering from it is almost always MUCH more
expensive than checking a pointer for null. It gets seriously ugly if you
are trying to control the granularity of the trap catching code, so you know
that an exception handled here could only be a pointer fault.
next prev parent reply other threads:[~2003-02-20 23:30 UTC|newest]
Thread overview: 135+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <mHZ0a.42983$jM5.108891@newsfeeds.bigpond.com>
[not found] ` <nRg1a.190899$HG.32437469@news4.srv.hcvlny.cv.net>
[not found] ` <3E51908E.9CCA3412@adaworks.com>
[not found] ` <8Gh4a.7455$_c6.743959@newsread2.prod.itd.earthlink.net>
[not found] ` <3E51ABCE.5491B9A2@adaworks.com>
[not found] ` <b2spe6$p23$1@helle.btinternet.com>
[not found] ` <3E5273DE.2050206@cox.net>
[not found] ` <3E531E6F.BDFB2599@adaworks.com>
[not found] ` <3E546C45.4010406@cox.net>
2003-02-20 15:49 ` status of PL/I as a viable language Richard Riehle
2003-02-20 16:26 ` Donald L. Dobbs
2003-02-20 17:15 ` Preben Randhol
2003-02-21 6:24 ` Anders Wirzenius
2003-02-21 18:44 ` John R. Strohm
2003-02-20 17:58 ` Hyman Rosen
2003-02-20 18:44 ` John R. Strohm
2003-02-20 19:09 ` Larry Kilgallen
2003-02-20 19:27 ` John R. Strohm
2003-02-20 19:48 ` Hyman Rosen
2003-02-20 21:12 ` John R. Strohm
2003-02-20 21:39 ` Bobby D. Bryant
2003-02-21 20:36 ` Randy Brukardt
2003-02-21 8:33 ` Jean-Pierre Rosen
2003-02-20 19:34 ` Hyman Rosen
2003-02-20 19:52 ` Vinzent Hoefler
2003-02-20 20:14 ` Hyman Rosen
2003-02-20 21:20 ` Vinzent Hoefler
2003-02-21 8:14 ` Ondřej Tučný
2003-02-21 14:54 ` Hyman Rosen
2003-02-21 15:05 ` Vinzent Hoefler
2003-02-21 15:55 ` Preben Randhol
2003-02-21 16:45 ` Hyman Rosen
2003-02-21 17:40 ` Preben Randhol
2003-02-21 17:44 ` Preben Randhol
2003-02-21 18:10 ` Hyman Rosen
2003-02-21 18:38 ` Preben Randhol
2003-02-21 18:40 ` Preben Randhol
2003-02-21 18:52 ` Hyman Rosen
2003-02-21 19:24 ` Vinzent Hoefler
2003-02-21 19:57 ` Hyman Rosen
2003-02-21 20:37 ` Vinzent Hoefler
2003-02-21 20:55 ` Randy Brukardt
2003-02-21 18:42 ` Vinzent Hoefler
2003-02-21 18:48 ` John R. Strohm
2003-02-21 20:22 ` Richard Riehle
2003-02-21 20:51 ` Randy Brukardt
2003-02-21 21:29 ` Hyman Rosen
2003-02-21 21:44 ` Vinzent Hoefler
2003-02-23 5:05 ` Hyman Rosen
2003-02-24 16:29 ` Vinzent Hoefler
2003-02-22 11:06 ` Preben Randhol
2003-02-23 22:04 ` tmoran
2003-02-24 9:32 ` Preben Randhol
2003-03-02 2:37 ` AG
2003-03-01 13:46 ` Preben Randhol
2003-03-03 0:57 ` AG
2003-03-02 12:40 ` Preben Randhol
2003-03-02 16:52 ` John R. Strohm
2003-03-03 0:19 ` Georg Bauhaus
2003-03-03 3:03 ` John R. Strohm
2003-03-04 12:11 ` Faust
2003-03-04 15:51 ` OT: Crime Frank J. Lhota
2003-03-03 8:01 ` status of PL/I as a viable language Preben Randhol
2003-02-24 20:15 ` Randy Brukardt
2003-02-25 10:00 ` Preben Randhol
2003-02-26 1:10 ` Randy Brukardt
2003-02-26 18:49 ` Stephen Leake
2003-02-27 12:09 ` Preben Randhol
2003-03-01 18:16 ` Richard Riehle
2003-03-02 1:56 ` AG
[not found] ` <iqeli-c2d.ln1@beastie.ix.netcom.com>
2003-02-23 5:13 ` Hyman Rosen
2003-02-28 10:32 ` Lutz Donnerhacke
2003-02-28 18:52 ` Vinzent Hoefler
2003-02-23 19:19 ` Berend de Boer
2003-02-24 6:19 ` Hyman Rosen
2003-02-20 22:10 ` Peter Flass
2003-02-20 22:26 ` Chad R. Meiners
2003-02-21 9:13 ` Dmitry A. Kazakov
2003-02-21 14:56 ` Hyman Rosen
2003-02-21 16:04 ` Preben Randhol
2003-02-21 19:41 ` Mike Silva
2003-02-21 20:41 ` Richard Riehle
2003-02-21 21:46 ` Donald L. Dobbs
2003-02-23 2:23 ` Shmuel (Seymour J.) Metz
2003-02-23 5:02 ` Hyman Rosen
2003-02-23 18:34 ` Donald L. Dobbs
2003-02-24 6:22 ` Hyman Rosen
2003-02-21 19:16 ` John R. Strohm
2003-02-21 19:49 ` Hyman Rosen
2003-02-21 20:32 ` Frank J. Lhota
2003-02-21 20:40 ` John R. Strohm
2003-02-25 10:31 ` Quality (Re: status of PL/I as a viable language) Anders Wirzenius
2003-02-25 13:10 ` Marin David Condic
2003-02-26 6:22 ` Anders Wirzenius
2003-02-26 11:47 ` Larry Kilgallen
2003-02-26 12:40 ` Larry Kilgallen
2003-02-26 13:43 ` Marin David Condic
2003-02-27 7:05 ` Anders Wirzenius
2003-03-01 22:28 ` AG
2003-03-01 12:56 ` Peter Flass
2003-03-01 19:17 ` Frank Clarke
2003-03-01 13:51 ` Anders Wirzenius
2003-03-01 13:54 ` Anders Wirzenius
2003-03-02 18:51 ` AG
2003-03-02 9:55 ` Anders Wirzenius
2003-02-21 20:35 ` status of PL/I as a viable language John R. Strohm
2003-02-21 21:40 ` Hyman Rosen
2003-02-21 22:25 ` John R. Strohm
2003-02-22 10:56 ` Preben Randhol
2003-02-22 19:55 ` Everett M. Greene
2003-02-23 11:15 ` Preben Randhol
2003-02-22 19:55 ` Everett M. Greene
2003-02-22 20:03 ` John R. Strohm
2003-02-22 22:38 ` Larry Kilgallen
2003-02-21 21:44 ` Pointless Harlows
2003-02-22 4:51 ` John W. Kennedy
2003-02-23 0:13 ` James J. Weinkam
2003-02-23 2:28 ` John W. Kennedy
2003-02-22 13:04 ` IEFBR14, was " Peter Flass
2003-02-22 19:08 ` Robert Munck
2003-02-23 9:53 ` Pointless Harlows
2003-02-22 19:31 ` John W. Kennedy
2003-02-23 2:12 ` Shmuel (Seymour J.) Metz
2003-02-20 21:45 ` Larry Kilgallen
2003-02-20 22:06 ` Peter Flass
2003-02-20 23:30 ` John R. Strohm [this message]
2003-02-21 13:46 ` Peter Flass
2003-02-21 20:33 ` Shmuel (Seymour J.) Metz
2003-02-21 20:26 ` Shmuel (Seymour J.) Metz
2003-02-20 22:34 ` Larry Kilgallen
[not found] ` <1lagi-b33.ln1@beastie.ix.netcom.com>
2003-02-21 16:09 ` Preben Randhol
2003-02-21 18:10 ` Larry Kilgallen
2003-02-24 12:00 ` Larry Kilgallen
2003-02-21 20:16 ` Shmuel (Seymour J.) Metz
2003-02-22 12:57 ` Peter Flass
2003-02-23 2:27 ` Shmuel (Seymour J.) Metz
2003-02-21 20:49 ` Donald's F-22 Question Richard Riehle
2003-02-21 22:37 ` Jerry Petrey
2003-02-20 23:00 status of PL/I as a viable language David C. Hoos, Sr.
-- strict thread matches above, loose matches on Subject: below --
2003-02-21 18:17 Lionel.DRAGHI
2003-02-21 18:44 ` Hyman Rosen
2003-02-22 13:26 David C. Hoos, Sr.
2003-02-26 20:55 David C. Hoos
2003-02-27 12:12 ` Preben Randhol
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